Single-cell encapsulation promises the cytoprotection of the encased cells against lethal stressors, reminiscent of the sporulation process in nature. However, the development of a cytocompatible method for chemically mimicking the germination process (i.e., shell degradation on-demand) has been elusive, despite the shell degradation being pivotal for the practical use of functional cells as well as for single cell-based biology. We report that an artificial shell, composed of tannic acid (TA) and Fe(III) , on individual Saccharomyces cerevisiae controllably degrades on-demand, while protecting the yeast from multiple external aggressors, including UV-C irradiation, lytic enzymes, and silver nanoparticles. Cell division is suppressed by the TA-Fe(III) shell, but restored fully upon shell degradation. The formation of a TA-Fe(III) shell would provide a versatile tool for achieving the chemical version of "sporulation and germination".

A cytocompatible method of surface-initiated, activator regenerated by electron transfer, atom transfer radical polymerization (SI-ARGET ATRP) is developed for engineering cell surfaces with synthetic polymers. Dopamine-based ATRP initiators are used for both introducing the ATRP initiator onto chemically complex cell surfaces uniformly (by the material-independent coating property of polydopamine) and protecting the cells from radical attack during polymerization (by the radical-scavenging property of polydopamine). Synthetic polymers are grafted onto the surface of individual yeast cells without significant loss of cell viability, and the uniform and dense grafting is confirmed by various characterization methods including agglutination assay and cell-division studies. This work will provide a strategic approach to the generation of living cell-polymer hybrid structures and open the door to their application in multitude of areas, such as sensor technology, catalysis, theranostics, and cell therapy.

Nanoshells F. Caruso, Y. Lee, I. S. Choi, and co‐workers show in their Communication on that a cytoprotective nanoshell can be formed on individual yeast cells from a coordination complex of tannic acid and FeIII ions.

Control over neurite orientation in primary hippocampal neurons is achieved by using interrupted, anisotropic micropillar arrays as a cell culture platform. Both neurite orientation and neurite length are controlled by a function of interpillar distance.

Single‐cell encapsulation promises the cytoprotection of the encased cells against lethal stressors, reminiscent of the sporulation process in nature. However, the development of a cytocompatible method for chemically mimicking the germination process (i.e., shell degradation on‐demand) has been elusive, despite the shell degradation being pivotal for the practical use of functional cells as well as for single cell‐based biology. We report that an artificial shell, composed of tannic acid (TA) and FeIII, on individual Saccharomyces cerevisiae controllably degrades on‐demand, while protecting the yeast from multiple external aggressors, including UV‐C irradiation, lytic enzymes, and silver nanoparticles. Cell division is suppressed by the TA–FeIII shell, but restored fully upon shell degradation. The formation of a TA–FeIII shell would provide a versatile tool for achieving the chemical version of “sporulation and germination”.